Ultrasound diagnosis apparatus, image processing apparatus and image processing method

1. An ultrasound diagnosis apparatus, comprising:

processing circuitry configured to

acquire a plurality of frames representing ultrasound images starting with an initial frame in time series;

compare a current frame and a previous frame to determine similarity therebetween, and generate a reference frame based on weighting processing on the initial frame and the previous frame using results of the similarity comparison; and

implement tracking processing between the reference frame and the current frame,

wherein the processing circuitry is further configured to implement the similarity comparison to increase a weight for the previous frame when the determined similarity is high and increase a weight for the initial frame when the determined similarity is low, and add the initial frame and the previous frame, which are subjected to the weighting processing, to generated the reference frame.

2. The ultrasound diagnosis apparatus according to claim 1 , wherein

the initial frame is a frame set with a region of interest, and

the processing circuitry is further configured to displace a position of the region of interest in the previous frame with respect to a region of interest in the initial frame before the adding.

3. The ultrasound diagnosis apparatus according to claim 1 , wherein the processing circuitry is further configured to implement the tracking processing between the current frame and the previous frame.

4. The ultrasound diagnosis apparatus according to claim 3 , wherein the processing circuitry is further configured to

perform matching between the reference frame and the current frame and between the current frame and the previous frame; and

calculate a first variation amount between a region in the current frame matched with the reference frame and a region in the reference frame corresponding to the matched region, calculate a second variation amount between a region in the current frame matched with the previous frame and a region in the previous frame corresponding to the matched region, determine, when the calculated first variation amount and the calculated second variation amount are both smaller than a threshold, that the tracking is successful, and, when at least one of the first variation amount and the second variation amount is greater than or equal to the threshold, determine that the tracking fails.

5. The ultrasound diagnosis apparatus according to claim 4 , wherein the processing circuitry is further configured to

implement forward matching and reverse matching both in the matching between the reference frame and the current frame and in the matching between the current frame and the previous frame, the forward matching referring to matching from any one of the reference frame and the previous frame as other frames to the current frame, and the reverse matching referring to matching from the current frame to the other frames; and

calculate, as the first variation amount, a differential between a region variation amount from the reference frame to the current frame and a region variation amount from the current frame to the reference frame, and calculate, as the second variation amount, a differential between a region variation amount from the previous frame to the current frame and a region variation amount from the current frame to the previous frame.

6. The ultrasound diagnosis apparatus according to claim 5 , wherein the processing circuitry is further configured to,

when implementing the forward matching between the reference frame and the current frame, set a region of interest in the reference frame before the matching as the corresponding region,

when implementing the forward matching between the current frame and the previous frame, set a region of interest in the previous frame before the matching as the corresponding region,

when implementing the reverse matching between the reference frame and the current frame, set a matched region in the reference frame after the reverse matching thereto from the current frame as the corresponding region, and

when implementing the reverse matching between the current frame and the previous frame, set a matched region in the previous frame after the reverse matching thereto from the current frame as the corresponding region.

7. The ultrasound diagnosis apparatus according to claim 4 , wherein the processing circuitry is further configured to

discard the current frame when it is determined that the tracking fails, and retain the current frame when it is determined that the tracking is successful.

8. The ultrasound diagnosis apparatus according to claim 1 , wherein the processing circuitry is further configured to

perform matching match between the reference frame and the current frame; and

calculate a variation amount between a matched region in the current frame and a region in the reference frame corresponding to the matched region, based on the matched region in the current frame, and determine, when the calculated variation amount is smaller than a threshold, that the tracking is successful, and, when the calculated variation amount is greater than or equal to the threshold, determine that the tracking fails.

9. The ultrasound diagnosis apparatus according to claim 8 , wherein the processing circuitry is further configured to

implement forward matching and reverse matching between the reference frame and the current frame, the forward matching referring to matching from the reference frame to the current frame, the reverse matching referring to matching from the current frame to the reference frame; and

calculate, as the variation amount, a differential between a region variation amount from the reference frame to the current frame and a region variation amount from the current frame to the reference frame.

10. The ultrasound diagnosis apparatus according to claim 9 , wherein the processing circuitry is further configured to set, in the forward matching, a region of interest in the reference frame before the matching as the corresponding region, and set, in the reverse matching, a matched region in the reference frame after the reverse matching thereto from the current frame as the corresponding region.

11. An image processing apparatus, comprising:

processing circuitry configured to

acquire a plurality of frames representing ultrasound images starting with an initial frame in time series;

compare a current frame and a previous frame to the current frame for determining similarity therebetween, and generate a reference frame based on weighting processing on the initial frame and the previous frame using results of the comparison; and

implement tracking processing between the reference frame and the current frame,

wherein the processing circuitry is further configured to implement the similarity comparison to increase a weight for the previous frame when the determined similarity is high and increase a weight for the initial frame when the determined similarity is low, and add the initial frame and the previous frame, which are subjected to the weighting processing, to generated the reference frame.

12. An image processing method, comprising:

acquiring a plurality of frames representing ultrasound images starting with an initial frame in time series;

comparing a current frame and a previous frame to determine similarity therebetween by implementing the similarity comparison to increase a weight for the previous frame when the determined similarity is high and increase a weight for the initial frame when the determined similarity is low, and generating a reference frame based on weighting processing on the initial frame and the previous frame using results of the comparison by adding the initial frame and the previous frame, which are subjected to the weighting processing; and

implementing tracking processing between the reference frame and the current frame.